The standard telnet utilities that ship with linux or windows allow to telnet to services running on TCP ports. They do not support udp ports. However the utility netcat can be used for working with udp ports in a very similar manner to default telnet utility.
The telnet utility works like this
$ telnet localhost 7000
where localhost is the hostname and 7000 is the port number. For udp ports the syntax for netcat is very similar
$ netcat localhost 7000 -u
The -u option indicates udp port.